Functional Vision Loss

Question 1

what are the two forms of functional vision loss?

Answer 1

malingering and hysteria

Question 2

what is functional vision loss?

Answer 2

the subjective complaints do not match the evaluation of the tissues or results of objective evaluation

Question 3

what is malingering?

Answer 3

simulation - making it up or faking condition

usually doing it for their own benefit or gain

Question 4

what is hysteria?

Answer 4

done for attention or exaggeration

not malicious = really believe they cannot see

Question 5

what are the typical demographic and triggers for hysteria?

Answer 5

pre-adolescent females

death in family, divorce, relocation, unemployment

Question 6

what are some tests used for monocular or binocular FVL with moderate and severe VA loss?

Answer 6

comprehensive evaluation, pupils, PAM, confrontation test

Question 7

what are some tests used for monocular or binocular FVL with moderate degree of VA loss?

Answer 7

quickly altering testing distance to see if acuity remains the same and a prolonged/delayed refraction with encouragement

Question 8

what are some tests used for monocular or binocular FVL with severe VA loss?

Answer 8

OKN, behaviors that are intact for the blind and behaviors that are absent in the blind

Question 9

what are some behaviors that are intact for the blind?

Answer 9

orient themselves towards people who are speaking, use vision-related words, and adept at using the vision they do have

Question 10

what are some behaviors that are absent in the blind?

Answer 10

avoiding objects in unexpected locations, navigating easily in strange places, reaching effiencetly for objects, making accurate saccades to small target

Question 11

what are some tests for monocular FVL with moderate or severe VA loss?

Answer 11

paired cylinder test, interruption with strong plus lens, prism dissociation

Question 12

what are some tests for monocular FVL with moderate VA loss?

Answer 12

reading bar test

Question 13

how can a tangent screen be useful in FVL?

Answer 13

the patients will have the same physical size VF at both 1 meter and 2 meter distances, usually circular 10-20 degrees, and may have spiral pattern

Question 14

what tests are used if you suspect malingering?

Answer 14

confrontation test, paired cylinder test, interruption with plus lens, prism dissociation, behaviors that are intact or lost in blind

Question 15

what tests are used if you suspect hysteria?

Answer 15

PAM, prolonged/delayed refraction, tangent screen

Question 16

what tests can be used for malingering or hysteria?

Answer 16

comprehensive evaluation of eyes, pupils, behaviors intact or absent in blind, quickly altering reading distance, OKN, reading bar

Question 17

what are the 5 differential diagnoses for FVL?

Answer 17

optic nerve disease, early keratoconus, mild amblyopia, early stargardt’s disease, central serous chorioretinopathy

Question 18

what is the management for malingering?

Answer 18

confront patient and tell them they have nothing wrong with them
set-up a follow up

Question 19

what is the management for hysteria?

Answer 19

wait and have patient come back for another exam - usually improves
can also refer to psychologist